METHANOL RECOVERY: BASICS, FINE TUNING, AND ENERGY BALANCE ISSUES Dickinson College Biodiesel Shop Carlisle, PA
What is methanol recovery? Biodiesel and Glycerin contain surplus methanol Methanol can be driven off via heating and captured for reuse May be done within biodiesel reactor or in standalone units Uses same procedures as making a batch
Why do methanol recovery? Removes toxic and flammable methanol from your biodiesel and glycerin Compliance with environmental laws Simplifies safe handling of fuel and byproducts Saves money and resources
How recovery works: methanol distillation basics Adding heat turns liquid methanol into methanol vapor (evaporation) Using water condenser cools vapors returning methanol to liquid state (condensation)
Plumber s Delight condenser
Booster condenser
Methanol recovery: how to do it
Methanol recovery: how to do it
Evaluating the purity of recovered methanol Biodiesel or Glycerin contains water in addition to surplus methanol Boiling point of water is 212 o F (100 o C) During recovery, fuel raised to above 240 o F Water vapors can potentially mix with methanol vapors Dilutes methanol during condensing stage
How to test the purity of recovered methanol
Running methanol recovery at the Dickinson shop
Methanol recovery road blocks Methanol recovery on glycerin Pro: glycerin is 30% methanol and yielded more methanol during recovery Con: increased amount of methanol overwhelmed 4 Plumber s delight condenser and produced greater amounts of wet methanol Alternative methods Booster condenser Re-circulated cooling Reflux column
Alternative methods: Booster Condenser
Alternative methods: re-circulated cooling
Alternative methods: reflux column
Basic reflux column design Item Quantity Price Total Price 2" to 3/4" Reducing Coupling 2 8.66 17.32 2" x 30" Black Steel Threaded Pipe 1 52.86 52.86 Copper Scouring Pad 5 3.99 19.95 3/4" x 3/4" x 1/2" Reducing Tee 1 4.45 4.45 3/4" Nipple 2 1.59 3.18 1/2" MPT Dial Type Temperature Gauge & Well 1 17 17 Total Cost: 114.76
Reflux column expectations Increased methanol purity Allow for successful methanol recovery with 5% pre-wash
Reflux column performance: methanol purity
Reflux column performance: methanol quantity
Reflux column performance: methanol content of glycerin Samples pulled at 240 o F, 250 o F, and 260 o F
Methanol Recovery Safety Biodiesel Contains 3-5% methanol Escapes into wash water Glycerol Crude glycerol contains about 25% methanol Classified as hazardous waste- toxic and ignitable Excess glycerol in the shop is a health and fire hazard. Plastic cubies of glycerol will leak with time Avoid stockpiling: have a plan!
What is Energy Work is a force applied over a distance. W = F x D Energy enables work. Kinetic Energy Thermal Energy Potential Energy Mechanical Energy Electrical Energy
Watts, Joules, and BTUs 1 Joule / second = 1 Watt 3,600 Joules / Hour = 1 Watt 3,600 Joules = 1 Watt Hour 3,600,000 Joules = 1 Kilowatt Hour (kwh) 1055.056 Joules = 1 British Thermal Unit (BTU) 3412.14 BTUs = 1 kwh
150 Watts 0.150 Kilowatts 511.821 BTUs 2 hours = 0.300 kwh Cost = 3 cents! 4,893.25 Watts 4.893 Kilowatts 16,695.6 BTUs 2 hours = 9.79 kwh Cost = 99 cents!
Importance of a Balanced Shop Fuel Efficiency Input : Output Research Opportunities Cost Analysis Electrical, Material, Labor
Shop Equipment Item VoltAmps Wattage Tuthill Pumper 667.00 246.79 1 Clear Water Pump 605.00 344.85 Reactor Heating Component Dry Tank Heating Component Bubbler 4,50 1,20 85 4,50 78 467.50
Material Input Input Cost Embedded Energy Gasoline $4.00/Gallon 125,000 BTUs Waste Vegetable Oil Free (For now) 0 BTUs New Methanol $4.10/Gallon 68,433 BTUs Recovered Methanol Free 0 BTUs Sodium Hydroxide (NaOH $2.43/Kilogram 11,247 BTUs Potassium Hydroxide (KOH) $8.44/Kilogram (not bought in bulk) 458.1 BTUs
Embedded Energy Efficiency of Electric Energy Systems Friction/Deformation Energy/Thermal Energy Energy costs of making chemical components. Methanol Sodium Hydroxide Potassium Hydroxide
Saving on Energy Solar Energy q = m t cp q: Change in energy t: Change in temperature of the solution ( C or K) m: The mass of the solution (kg) Cp: Specific Heat Capacity (J/kg*K) q = 2.424kg 1.6 C 3342.4J/kg*K q = 12,963J = 12.29BTUs
Saving on Energy Methanol Recovery Recovered methanol contains no embedded energy Production costs decrease for the next batch
Spread Sheet Microsoft Excel Worksheet
Back Up Plan! Processing Step Device VoltAmp Pf of Device Average Wattage Time (hours) Kilowatt hours BTU per kwh (energy used) Total energy (BTU) Pump Oil into Storage Tuthill 667.00.37 246.79 0.08 0.02 11,383 224.74 Pf x VoltAmp (.001) x time x wattage 3x BTU/kWh BTU x kwh
ELECTRICAL INPUTS A. Process step B. Device C. VoltAmp D. Pf of Devic e E. Average Wattage F. Time (hours) G. Kilowa tt hours (E X F X 1) J. BTU per kwh (energ y used) L. Total energy this step (BTU): (G x J) Pump Oil into Storage Pump II 667.00 0.37 246.79 11,383.30 Preheat Oil in Storage Solar Heating 8 0.65 52.00 11,383.30 Pump Oil into Appleseed Reactor Pump I 605.00 0.57 344.85 11,383.30 Preheat Oil in Reactor Reactor Heating Component 4,50 1.00 4,50 11,383.30 Mix Oil while Heating Pump I 605.00 0.57 344.85 11,383.30 Mix During Reaction Pump 1 605.00 0.57 344.85 11,383.30 Pump Glycerin out of Appleseed Reactor Pump I 605.00 0.57 344.85 11,383.30 Heat Fuel during Methanol Recovery Reactor Heating Component 4,50 1.00 4,50 11,383.30 Mix Fuel during Methanol Recovery Pump I 605.00 0.57 344.85 11,383.30 Pump Fuel into Settleing Tank Pump I 605.00 0.57 344.85 11,383.30 Pump Fuel into Wash Tank Pump I 605.00 0.57 344.85 11,383.30 Pump Fuel into Dry Tank Pump I 605.00 0.57 344.85 11,383.30 Bubble Dry Bubbler 85 0.55 467.50 11,383.30 Heat Dry Dry Tank Heating Component 1,20 0.65 78 11,383.30 Mix Fuel while Drying Pump I 605.00 0.57 344.85 11,383.30 Total Time: Total kwh: Total BTUs:
Output:Input Analysis $1.94 4.81 6,415,00 450,800.82 882,623.75 #9 $2.10 4.62 6,415,00 533,665.33 855,636.76 #8 $219.62 213,390.31 855,572.63 #7 $2.15 5.03 6,415,00 420,901.70 855,572.63 #6 $2.11 5.25 6,415,00 367,206.96 855,600.11 #5 $2.10 4.05 6,415,00 702,82 879,394.59 #4 #3 #2 $1.99 4.94 6,415,00 418,559.41 879,394.59 #1 Cost Output:Input Ratio Total Output Electrical Input Material Input
$2.07 per Gallon Increase batch sizes Differentiate between recovered methanol and new methanol used in batched Buy materials in bulk
Considerations for the Future Better Record Keeping! Embedded Energy of Recovered Methanol Reflux Column for Methanol Recovery from Glycerin